Polymer positive temperature coefficient (PPTC) devices may be used as overcurrent or over-temperature protection devices, as well as current or temperature sensors, among various applications. In overcurrent or over-temperature protection applications, a PPTC device may be considered a resettable fuse, designed to exhibit low resistance when operating under predetermined conditions, such as low current. The resistance of the PPTC device may be altered by direct heating due to temperature increases in the environment of the PPTC device, or via resistive heating generated by electrical current passing through the PPTC device. For example, a PPTC device may include a composite PPTC material formed of a polymer material and a conductive filler, wherein the PPTC material transitions from a low resistance state to a high resistance state due to thermally-induced changes in the polymer material, such as a melting transition or a glass transition. At a transition temperature, sometimes called a “trip temperature,” where the trip temperature may range from room temperature to well above room temperature, the polymer material may expand and disrupt the electrically conductive network of conductive filler particles in the PPTC material, rendering the PPTC material much less electrically conductive. This change in resistance imparts a fuse-like character to PPTC materials, which resistance may be reversible when the PPTC material cools back to room temperature.
The cost, weight, and performance characteristics of a PPTC material are largely influenced by the type and quantity of conductive filler in the PPTC material. It is with respect to these and other considerations that the present disclosure is provided.